Liquid control



Dec. 12, 1939. w, J, H GHES LIQUID comm.

Filed Nov.. 29, 1935 8 Sheets-Sheet 1 ubmmo Dec. 12, 1939. w. J. HUGHESLIQUID CONTROL Filed Nov. 29, 1935 8 Sheets-Sheet 2 w. J. HUGHES LIQUIDCONTROL Filed Nov. 29, 1935 8 sheet t 3 Dec. 12 1939- vw. J. HUGHESLIQUID CONTROL Filed Nov. 29. less 8 Sheets- Sheet 4 i WaZZfJHugh W, M*M

Dec. 12, 1939. w, J, HUGHES 2,183,075

LIQUID CONTROL Filed Nov. 29, 1935 8 Sheets-Sheet J04 J03 J01 4 97 88 la5 6 1 r a 40 74 77 i-ll l I a z 2 e 6 55 1 i I a l v 5 Dec. 12, 1939.w. J. HUGHES 2,183,075

LIQUID CONTROL 8 Sheets-Sheet 6 Filed NOV. 29, 1935 mw NAN m3 5 m9 5 m9."mw H Dec. 12, 1939. w J HUGHES 2,183,075

LIQUID CONTROL Filed Nov. 29, 1935 a sheets-sheet 'r ESQ Dec. 12, 1939.

w. J. HUGHES LIQUID CONTROL Filed Nov. 29, 1935 8 Sheets-Sheet 8 mm fiMn N %1 x v m g a Patented Dec. 12, 1939 PATENT OFFICE LIQUID CONTROLWalter J. Hughes, Chicago, Ill., assignor, by mesne assignments, toInfilco Inc., a corporation of Delaware Application November 29, 1935,Serial No. 52,054

16 Claims.

The present invention relates to water filtration plants and othersimilar plants and their operation, and has particular'reference to animproved method of operating and to control mechanism for such plantsinvolving a unified system for carrying out the cycle of operationsnecessary in the normal operation of a gravity type of water filtrationplant. A

V The ordinary filtration plant such as may be employed in city watersupply systems generally includes a number of gravity operatedfiltration units having beds of relatively large size. The completefiltration process requires in each filter unit a cycle of steps. Eachof the several units of such a filter plant is ordinarily complete initself but there generally is some common service feature which isinadequate to serve all simultaneously, and perhaps not more than oneunit at a time.

Up to the present time all such plants have been hand operated andcontrolled. Some automatic devices are used, as for instance a'flowcontroller on the discharge line from each unit to control the rate offiltration thereof to a set 25 amount. Also gauges or indicators areprovided to show various conditions as they exist in the several units.With such helps the operation of the plant is controlled by attendants,who manually open and shut or control the opening and closing of thevarious valves by which the plant or the several units may be served.This involves constant supervision so that care be given as required,and as most such plants are operated twenty-four hours per day, threeshifts of attendants are required although there may be lengthy periodswhen there is no work to be done. A principal object of my invention istherefore to provide a method of operation and apparatus therefor thatmake this constant and 46 close supervision and attention unnecessary byproviding for the automatic control and operation of the individualunits and of the plant as a whole. A further object is to provide forthe coordination of the operation of the individual 3 units comprised insuch a plant so that therev will not be interference.

Another object is to provide for the operation of a single unit on atime control basis and also where a plurality of units are associated tocorrelate their operation on a time basis.

Another object is to provide for a control of the operation of a unitfrom or by some condition in the unit or its operation and to then alsoappropriately correlate the operation of the members of a group ofunits.

A principal object of my invention is to provide a method and apparatusfor operation of gravity type filter units singly and in groupedrelation based upon a predetermined cycle of operation.

An additional object is to provide an automatic apparatus for operatingthe members of a group of filter units through a series of operatingsteps in such a manner that the steps of the various filters arecoordinated, while at the same time 10 any of the steps may be prolongedWithout disturbing the subsequent normal operation.

A further object is the provision of a filter control mechanism of thetype referred to in which the operation of a filter unit is automati- 15cally carried out through a program of steps occurring at timedintervals over a fixed period, an automatic timing device being providedtherefor and there being additionally, means for suspending operation ofthe timing device when 20 circumstances or convenience requires.

A special object of the invention is the provision of a central timingdevice for the operation of such filters in which there is providedmeans for starting the device and for stopping it at the '25 end of afixed period of time, the device beingoperable after the start of theperiod to make an initiating circuit that will terminate an untimedfirst function and'start a second function, simul- 'taneously breakingthe initiating circuit; after an adjustable period of time to make asecond initiating circuit that will terminate the second function andstart a third function, simultaneously breaking the second initiatingcircuit; and to repeat this process through a series of five separatelytimed functions. At the end of the time for the last function the devicemakes a fifth initiating circuit which will terminate the fifth functionand restore the untimed first function, at the same time preparing thecircuit for 40 again starting the device, all the above being completedwithin the period provided.

Another special object is the provision of'a filtration control systemwhich has adjustable timing devices automatically controlling the timeintervalsof operating each of the filters of the system through thesteps of drainage, washing, rewashing and return to filtering.

Another object is to provide an automatic filter control system in whicha timed cleansing program is initiated by and carried out upon apredetermined loss .of head in the filter unit.

A still further object of the invention is to provide a filter systemcontrol in which a central selector controls the sequence of action of aplurality of timing members which in turn control multi-positionedvalves operatively connected each to the valves of a unit of a gravityfiltration system that comprises a plurality of units.

A further object is the provision of an improved hydraulic control valvefor operating filters and the like.

Another object of the invention is the provision of automatic groupcontrol of a filtration system combined with automatic operation controlof the units thereof.

These and other objects will be evident from a consideration of thefollowing specification in which there is described for purposes ofillustration and explanation a preferred embodiment of the invention,and by reference to the accompanying drawings, in which Fig. 1 is adiagrammatic chart of a filter control constructed in accordance with myinvention;

Fig. 2 is a similar chart showing two of the units of Fig. 1 in a systemalso having loss of head initiating devices and a central selector;

Fig. 3 is a diagrammatic sectional view of a main control valveconstructed in accordance with my invention;

Fig. 4 is an end view partially in section, of a conventional gravityfilter with front piping and valves;

Fig. 5 shows in elevation the left valve disk of the valve shown in Fig.15;

Fig. 6 is a sectional view taken along line 6-6 of Fig. 5 and showingthe disk of Fig. 5 superimposed upon the left side set of ports of Fig.3 as in A functional position; i

Fig. '7 is a view of the right valve disk of the valve shown in Fig. 15

Fig. 8 is a sectional View taken along line 8-8 of Fig. 7 with the diskshown superimposed upon the right side set of ports of Fig. 3.as in Afunctional position; I

Fig. 9 is a sectional view of the valve shown in Fig. 15 as in Bfunctional position, the discs being shown in section.

Fig. 10 is a view similar to Fig. 9 showing the valve in C functionalposition;

Fig. 11 is a view similar to Fig. 10 but simplified, showing the valvediscs in D functional position;

Fig. 12 is a view similar to Fig. 11 showing the valve discs in Efunctional position;

Fig. 13 is a view similar to Fig. 11 and shows the valve discs in Ffunctional position;

Fig. 14 is a view similar to Fig.- 11 showing the.

valve discs in Gt functional position;

Fig. 15 is a front view, partially'in section of the main control valveof Fig. 3 with a driving mechanism and pipes leading to the valvecylinders;

Fig. 16 shows the dial of the. function indicator;

Fig. 17 is a side view partially in section of the function indicatordial of Fig. 16 and shows drive mechanism therefor;

Fig. 18 is a wiring diagram of electrical control circuits employed inaccordance with the invention;

Fig. 19 shows mechanism and wiringdiagram for initiating the washingprogram of a filter unit upon a predetermined loss of head' therein;

Fig. 20 illustrates the mechanism and wiring of Fig. 19 extendedto'cover two filters, with means for preventing more than one of thefilters from being washed at a time;

Fig. 21 is a detail view of a portion of Fig. 20; and

Fig. 22 is a view similar 'to that of Fig. 20 but of a modified form aspreferred to take care of a larger number of filter units.

' In the operation of a gravity filter a cycle comprising two generalsteps is involved. The first is that of fi1tration-0f the water whileiheseg 0nd, which is that of cleansing the bed, involves a series ofoperations. This series of operations includes cutting off the supply tothe filter to drain down the water above the bed, the latter beingcommonly done by filtering off this water to conserve it. The nextoperation is that of actually washing the filter with an upward orreverse flow of wash water. The last operation is that of putting thefilter bed in proper condition for filtering service which is done byfiltering to waste for a short time.

The first or filtering step is relatively long, often being of from 20to hours duration, this time being dependent upon such factors as rateof filtration and amount of sediment in the water being filtered sincethese factors determine the rapidity of clogging of the filter bed byaccumula tion of sediment. As the clogging increases it is evidenced bygreater resistance to flow through the bed, a condition commonly spokenof in practice as loss of head.

Since in gravity filter operation only so much water head is availableto cause flow, it is obvious that as filtration continues clogging willeventually cause the rate of filtration to slow down to an extent thatfurther operation is not economical or else not desirable for otherreasons. This end point is usually determined when a desired fixed rateof filtration can no longer be maintained, that is, when the headavailable is so consumed by clogging that filtration is retarded. Thusthe loss of head usually is the measure by which the end point of thefiltration step is determined. When this loss amounts to about ten feet,good practice dictates that the filter bed be washed.

In order to carry out the second or cleansing step of the cycle, theseveral operations described above are executed in set order, and forordinary conditions they involve fairly well fixed time periods. Thusthey may be carried out in an orderly program as to sequence and time,means of course, being provided for changing the timing of the periodsto suit changes in conditions.

The carrying out of the series of operations included in the cleansingof the bed and its return to service involves a number of consecutiveactions. The first, or B action, when the second step of the cycle isput in force, is cutting off the supply to the filter by closing theinfiuent valve.

The second, or C action, after allowing the filter to drain through itseffluent for a given time, is to close the efliuent valve and open thewaste valve.

The third, or D action, after allowing time for eflluent valve to closeand waste valve to open, is to open the wash valve.

The fourth, or E action, after allowing time for effective washing, isto close both wash and waste valves.

- The fifth, or F action, after allowing time for closing of the washand waste valves, is to open the infiuent and rewash valves.

The sixth, or G action, after allowing time for a short rewash, is toclose both influent and rewash valves. This provides a shut-off positionsince all valves are closed.

The seventh, or A action, is to restore the filter to service by openingits influent and eflluent valves.

The actions themselves consume time in that large size hydraulicallyoperated valves take time to open and close without slamming and withoutcausing damaging water hammer. And the operations controlled by thevalve action and that later take place between the valve actions, alsoconsume time.- Thus the second step of the cycle as to timingand'sequence of its included actions and operations, may be tabulated asfollows, the lettering used being referred to hereinafter: It will. beunderstood, of course, that the times given are for illustrativepurposes and may not correspond to the times allowed in practice.

Control Elapsed val-v9 Action time, Operation functional minutcs,position B Close infiucnt valve (20- Start of draining minute drain toefiluto effluent. ent

C Close efiluent valve and 20 End of draining.

open waste valve. (2 minutes for valves to operate).

D Open wash valve (10 22 Start wash.

minutes for washing).

E Close wash and waste 32 End wash.

valves. (2 minutes for valves to operate).

F Open influent and re- 34 Start rewash.

wash valves. minutes for rewashing).

G Close influent and re' 39 End rewash.

wash valves.

Filter off.

A Open influent and eil'lu- Filter on.

ent valves.

For this method of operation, five hydrauhcally operated gate valves arerequired, the valves being termed, respectively, infiuent, efliuent,Waste, wash and rewash. The hydraulic cylinders that operate to open andclose these valves are connected in the usual manner to a source ofpres- Thus one end of a cylsure and a waste line. inder may receivepressure water to act on one side of a piston therein while the otherend is relieved to waste or vice-versa, in order to /move the piston toeither open or close the valve to which the piston is attached by asuitable rod.

Control of the admission of pressure water to one end of the cylindersand the escapement from the opposite cylinder ends to effect" valveopening or closing motion, is by means of a main control valve. Thisvalve is motor-operated and has seven positions which by portarrangement control respectively the seven actions tabulated above.Positioning of this valve to carry out the several actions in thepredetermined time and sequence is controlled by means of a timer sothat in my improved apparatus the operation of each filter is automatic.Further, a central timing selcctor is provided that supplies thestarting impulse for each unit timer so that the operation of theseveral units of a filter system are coordinated as well as automatic.

In order that a general understanding of the I relation of the mainparts of my apparatus may be had before going into details of theconstruction and operation of these parts or referring to the numerousconnections and cooperating parts, reference is made to the purelydiagrammatic charts of Figs. 1 and 2. Thus in Fig. 1 a single filterindicated by It) is shown subject to the several operating valves I ll5,which are all under control of a control valve I6. Control I G is inturn vsubject to the timer I1 and also to push-buttons 20 and 2|, andtimer I1 is under pushbuttons l8 and I9. Stated briefly, closingpushbutton I8 will start timer I1 which will normally control valve I8through a series of positions to operate valves II-I5 to take filterIII'oif from filtering, put it through the several steps of thecleansing process and restore it to filtering. Since it may be desirednow and then to prolong one of the steps beyond its normal period thisis provided for by the button I9, which will'stop timer I! in anyposition so long as depressed. Also since it is desirable to be able tocut a filter out of service and later restore it at irregular times,push-bottons' 20 and 2I are provided which control operation of valve l6without going through timer II. If button 20 be depressed valve IE willshift to off' position, controlling valves I I-I5 to cut the filter outand it will remain out until button 2| be depressed which will cause I6to shift back to on position, operating valves I Il5 as necessary to putI0 back in service.

Fig. 2 shows the same parts in the same relation as in Fig. 1 but induplicate to indicate a plant having two units. There are also shown twoadditional members 22, one for each unit. These members 22 indicatemeans for initiating operation of timer I! automatically from conditionsin or about the filter unit, as from a loss of head gauge, and areaccordingly shown in parallel with buttons I8. Since this opens thepossibility of both timers I! being started so as to be in operation atthe same time, which is undesirable, the members 22 are shown connectedthrough another new member 23, which serves to prevent both circuitsthat include the member 22 being closed at the same time and also, afterone such circuit has been closed, to hold the other open for apredetermined period or until the other timer I! has completed itscycle.

The manner in which these general control operations are carried outwill be better understood by reference to the following more detaileddescription of the filter system.

i As shown in Fig. 4 the numeral I 0 indicates there rests a bed offilter sand 28. A system of .wash water collecting troughs 29 connectsthrough the front wall of the filter to the T 30.

The water to be filtered enters through influent pipe 3| from a suitablecoagulating basin or other source of supply through infiuent valve H tothe T 30. From this-T the water passes into the filter basin in whichthe level is maintained at the level 32 by any suitable means.

During filtration the water passes downwardly through the filter bed 28and supporting material 21 and is collected by the'underdrain system ofpiping 24. From this underdrain system the Water fiows to the centralheader connected to the T and thence through valve I2, the effluent rateof flow controller 33 and the etlluent pipe 34 to storage or use.

During the filtering operation (function A) the infiuent valve I I andthe efiluent valve I2 are open, and the waste valve I3, the wash valveI4 and the rewash valve I5 remain closed.

When it becomes necessary to wash the filter bed, the influent valve IIis closed to cut off the 18 supply of coagulated water. For a period ofperhaps twenty minutes or less the filter is permitted to drain throughthe effluent to conserve the coagulated water that is in the upper partof the filter basin (function B). When the level 32 is dropped to aboutthe top of the wash troughs 29 the eflluent valve I2 is closed and thewaste valve I3 is opened to drop the level 32 to'the top or lip of thewash troughs 29 (function C).

Thereafter, the filter is ready for the actual washing operation whichis started by opening the wash valve H. The wash water is deliveredfilters and the controller 38 may then well be in the header instead ofhaving a separate controller in each branch.

After a period of say 10 minutes the washing is I terminated by closingboth the wash valve l4 and the waste valve l3 (function E), time beingallowed for these two valves to completely close.

The next operation comprises opening the infiuent valve II to refill thefilter basin to the level 32 with coagulated water, and opening rewashvalve l5 to permit filtering to waste through 39 in order to put thefilter bed in condition before resuming filtering to service.

- In the nextoperation the influent valve ii and the rewash valve l5are-closed to terminate the rewash and bringall valves of the filter totheir closed position. In such position the filter is off. The filtermay merely pass through this position and be restored toserviceimmediately by opening the influent valve H and the eiliuentvalve l2, or this restoration to service may be delayed.

It will be'understood that the particular times given in connection withthe description of the several functions are for illustration only. .Theactual timeswill vary in different plants, depending upon factorsincluding details of construction and the character of the water. In

some instances it will be found desirable "to change the timing of oneor more of thefunctions atdifierent seasons, or for other reasons. Inaccordance with my invention I provide means for a wide range of timeadjustment for each of the functions without loss of time through blankspaces, the total time from off to on position being simply the sum ofthe times allotted to the several functions regardless of what these maybe. The filtering step is by far the longest step in the cycle ofoperations and usually will be indeterminate as to time, the actual timebeing that required for the filter to become clogged.

In Figs. 3, 6, and 8 to 14, the improved valve mechanism is disclosed invarious operating positions. This valve has two complementary discs withcorresponding seats and ports. The leads to the corresponding ports ofthe two seats are connected to opposite sides or the hydraulic pistonsby which the valvesof the filter unit are opened and closed. The leftunit is provided with ports 42, 43, 44, 45 and 48, positioned as shownin Fig. 3 and the right unit contains corresponding ports 41, 48, 49, 50and 5|. Ports 42, 43, 44,

45 and 48 lead through pipes 53, 54, 55, 58 and 51 respectively, to thelowerends of the hydraulic gate valve cylinders 58, 5 9, 88, 8i and 52,respectively. Cylinder 58 controls influent valve H, cylinder 59'.controls efiiuent valve 12, cylinder 5 88 controls the waste valve l3,cylinder 5| controls wash valve l4 and cylinder 52 controls the rewashvalve N. In the right side of the valve, port 41 leads through pipe 83to the upper or closing end of the hydraulic gate valve cylinder I 58.Port 48 connects through pipe 84 to the closing end of cylinder 59. Port49 connects through line 85 to cylinder 58 Port 50 connects through line88 to the closing end of the cylinder 8|. Port connects through line 81to the clos 5 ing end of cylinder 82..

Water under pressure is introduced at 88 into the chamber 40 in thecover above the valve discs while from under the discs water may escapethrough ports 52 and I8 and channels H to pipe 12 (Figs. 3 and It willbe understood that the operation of the double valve is such that tooperate any one of the gate valves water under pressure is directed toone end of its hydraulic cylinder through the proper port on one diskwhile the other end of the cylinder is opened towaste through thecorresponding port on the other disk.

The position into which the control valve discs are placed to startfiltration and in which they 39 remain-during the filtration period(function A), is shown in Figs. 6 and 8. Referring to these figures, andalso to'Figs. 3, 4'and 15 it will be seen that pressure water fromchamber 48 enters through recess 18, port 42 and pipe 53 to the bottomof cylinder 58 to openinfiuent valve H and hold it open, water from theupper end of 58 escaping through pipe 88, port 41, recess 19, port" andchannel 'II to vent I2. At the same tinie eiiiuent valve 12 is openedand held open 'by/water from chamber 48 entering through recess 18, port48 and pipe 54 to the bottom of cylinder 59, escape of water from thetop of 59 being through pipe" 84, port 48, recess '|9, port 10 andchannel II to vent I2. During this period 5 valves l8, l4 and II areleft closed by pressure transmitted to the tops of their cylinders fromchamber through recess 82 and ports 49, 58 and 5| in the right-handside, the bottoms of these cylinders being open to waste through ports44, 45 and 48, recess 80, port 52 and channel II to vent 12.

In Fig. 9 the discs are shown in the positions into which they arerotated to drain down the water above the filter bed (function B). Atthis timepressure water from 48 still reaches the bottomof cylinder 59through recess 18, port 43 and pipe 54, the top thereof being relievedthrough pipe 84, port 48, recess 19, port 18 and channel H, to vent 12,to hold eiiiuent valve. open. Infiuent valve ll shifts to closedposition because pressure water now has access to the top of cylinder 58from chamber 48 through recess 82, port 41 and pipe 58, the bottom ofthe cylinder now being relieved through pipe 53, port 42, recess 80,port 52 and channel H to vent 12. The other valves remain in closedposition since the pressure and waste connections to their cylinders arenot altered.

It will be seen in Fig. 15 that the two valve 70 discs 14 and H areprovided with hubs indicated at 83 and 84, by which the discs areloosely keyed to their respective centering and turning shafts 85 and88. Shaft 85 is joumaled at 81 and 88, while shaft 88 is jouinaled at 89and 98. 78

A gland 9| is provided on shaft 85 and a corresponding gland 92 isprovided on shaft 85. To shaft 85 is keyed a spur gear 93 which mesheswith a similar gear 94, keyed on shaft 88, thereby insuring synchronousrotation of the valve discs. Spring 95 maintains the disk I4 properlyseated, and spring 96 acts likewise upon disc 11, the upper ends of thesprings pressing against collars 9! and 98, respectively.

Shaft 85 extends above its upper journal 88 into the worm gear housing99, where it is pinned to the worm wheel I00, the latter being driven bythe worm I on the extended motor shaft I02 of motor I03. This manner ofdriving the two valve disks causes them to rotate in unison but inopposite directions.

In Figs. 15, 16 and 17 the shaft I04 is shown extending from the shaft85 and through the bevel gears I05 turning shaft I05 to which isattached pointer I08. Pointer I08 moves over the face of dial I0! and byits position thereon indicates the position of the control valve and sothe function in which the filter rests or to which it is shifting.

Fig. 10 shows the position into which the two discs I4 and II are turnedto open waste valve l3 and close effluent valve I2 (function C) Pressurerecess I8 of valve disk 14 now uncovers port 44 while waste recess "ofvalve I4 connects ports 42, 43, 45 and 4 5 to waste port 52. Recess I9of 'valve disk 11 connects port 48 to waste port 10 while the pressureport 82 of valve disk 1! con-- veys pressure to ports 41, 48, 50 and 5I.From Figs. 3, 4 and 15 it will be seen that with the ports so arrangedall valvesof the filter are closed except the waste valve I3, which isopened. When effluent valve is closed valve I4 may be opened to admitwash water and Fig. 11 shows the position of the two valve discs I4 andIT with respect to the valve seat ports when turned to the next positionfor this purpose (function D). Pressure recess I8 of valve disk I4 nowuncovers ports -44 and 45 to pressure, and waste recess 80 connectsports 42,-43 and 46 to waste port 52.

Waste recess I9 of valve disk II connects ports 49 and 50 to waste portI0 and recess 82 of valve 11 transmits pressure to ports 41, 48 and 5|.Thus as may be seen from' Figs. 3, 4 and '15, all valves of the filterare closed except wash valve I4 and waste valve I3 which are open duringfunction D to wash the fllter.

When washing is completed a further turning of the discs brings them tothe position of Fig. 12

where the two valve discs I4 and 11 are shown 1 with respect to thevalve seat ports when turned 52, and valve disk 11 bringsall seat portsto pressure throughside opening-82 so that all valves of the filter areclosed.

After allowing the time necessary for closing of these valves thecontrol valve is 'again turned as indicated in Fig. 13 which shows theposition ofthe two discs with respect to the seat .ports during therewash period (function F). Pressure recess I6 and pressure port I09 ofvalve disk I4 now convey pressure to ports 42 and 48 while waste recessof valve disk I4 connects ports 43, 44 and 45 to waste port-52. Wasterecesses I8 and H0 of valve disk II'connect ports 41 and 5I to wasteport I0 while pressure recess 82 of valve disk I! conveys pressure toports 48.v 49 and 50. As is seen from Figs. 3, 4, 13 and 15, all valvesof the filter are'now closed except infiuent valve II and rewash valveI5 but pressure water is admitted to the bottom of the hydrauliccylinders on these two valves, the'tops being relieved to waste.

Fig. 14 shows the position of the two valve discs with respect to thevalve seat ports when turned to the position of function G. Thisposition is an off position adjacent the filter on position of functionA. During function G all ports of seat I5 are connected to waste throughrecess 80 of disk valve I4 while all ports of seat I8 are connected topressure through side opening 82 of valve disk 1]. Thus, as seen fromFigs. 3, 4 and 15, all valves are closed, as they should be in this offposition.

It will thus be seen that the operation of a filter unit is controlleddependent upon the position of the valve discs I4 and 11. Each unit of asystem is operated by its own main control valve and, as will bedescribed hereinafter, each main control valve is governed by a timecontrol system whereby the filter may be carried through a cycle ofoperations as desired.

In Fig. 18 is illustrated diagrammatically the electric circuits,relays, timer, function position stop switches,'main valve motor andpush-button station for a control system for carrying out or effectingthe proper program of functions in accordance with my invention.Provision is made for operation of a filter as follows: To take it fromfiltering function A, carry it through the functions B, C, D, E, F, Gand return to A; to start from A carry through automatically thefunctions B, C, D,'E, F and stop at off position G; to later shift fromoff position G to filtering position A; to shift from filtering functionA to off position G; for individually adjusting the length of theperiods allowed for functions B, 'C, D, E and F; and for prolonging atwill the period of any of functions B, C, D, E or F during any cyclewithout changing the setting con'- trolling the regular period thereof.

Fig. 18 will be more readily understood by considering it as separatedinto two groups of circuits, namely, the timer circuits'and the mainvalve motor control circuits. The purpose of the timer circuits is tosecure one revolution of the timer shaft I52 in a given time, in thiscase taken as 45 minutes,-to move the contactor I53 which is mounted onshaft I52, across the several contacts, and to stop thetimer at thecompletion of the revolution. Tracing from X, the terminal of source ofenergy I I I, the lead I I2 carries the circuit through the mercuryswitch I I3, shown closed as in the function A position of the cam I90,through lines 3 and I I5 of the normally closed push-button switch 20,and line II6 to one terminal of the normally open pushbutton switch I8.To initiate the next ensuing program, the button I8 ismomentarily'depressed to this time carry the circuit from line I I6through leg I I1 of switch I8, to line H8. The next program is initiatedin the same manner except that the circuit is completed from line I I6through I II to line I I9, and so on alternately, as willbe furtherexplained.

This circuit leads through line 8 to line I22,- through the closedmercury switch I24, lead I26, magnet coil of relay HI and line I32 toterminal Y of energy source II I, thereby energizing the magnet coil ofrelay MI and clos- -toYof source III.

scribed conditions because mercury switch I25 is open.

Again starting at ,the source, terminal X of III, the line II2 leads tothe now closed switch of relay l4I, 'pigtail p, line I20, line I22,switch I24, line I26, the magnet coil of why I andlineI32toterminalYofsource III. Thus depressing the button I8momentarily closes the switch by line I 32 with terminal Y of the sourceof energy. III.

The energized motor rotates shaft I52 through one complete revolution of360 in 45 minutes,

and being geared to the cams I48 and I49 by a one-'to-two ratio gearing,turns the cams through a half revolution or 180. The two cams are shapedalike but set 180 apart so that for each half revolution of the earnsthe rollers of the two mercury switches I24 and I25 will cause reversalof their positions as to being open and closed. As shown, switch I24 isclosed and switch I25 is open. Upon making a half revolution, the camI48 will cause the switch I25 to tip to its closed position; and the camI49 will drop the switch I24 to its open position, springs I88 and theshaping of the cams providing iorv snap action. Thus, the holdingcircuit through the pigtail p of relay I, the switch I24, the, coil ofrelay I and line I32 is broken; the relay I M breaks the circuit of themotor I29 and the latter, upon making a complete revolution of its shaftI52 stops, the switch I25 having been tipped to its closed position justbefore the stop.

When the next program is'started by again depressing the button I8 thisnow completes the circuit through line II9, line I23, the now closedswitch I25, line I21, the coil of relay I42 and line I32 to source I II. Thereupon, the holding circuit is made from X of source II I, lineM2, the switch of relay I42, pigtail p, line I2I, line I23, switch I25,line I21, the coil of relay I42, and line I32 Before considering theother circuits, attention is called to relay I45 which is of thenormally closed type and whose. coil is in thecircuit of elements I28 toI 32 in parallel with the'telechron motor I29. Thus, when either of thecircuits above referred to is closed, the switchof relay,l45

is open to break a circuit between lines I33 and I32, which circuit willbe dealt with hereinafter.

The main control motor I03 is of the reversing type.

The circuits controlling operation of valve motor IDS-include thecontactrarm- I53 of the timer I and the contacts l13, I14 and I15, the

Likewise, the circuit is comlatter two of which are adjustable in grooveI84 in the dial of timer I85. Also included in these circuits are thecontacts I18, I11 and I13, all of which are adjustable in the grooveI84; pushbuttons 2! and 20; the mercoid switches I8I, I54, I59 and I61held in their respective positions by the main valve cams I81, I88 andI89. Since it is desirable that all of the timer controlledcircuits'whose contacts are locatedupon the timer dial I85 should be oflow voltage, a transformer I93, connected to the high voltage source IIIthrough leads 2 and I32, delivers low voltage energy to the lines I58and I10. r

Before tracing these control circuits, it will be pointed out that thetwo push-buttons 2| and 20 are of the conventional spring toggle type sothat when one is closed the other opens. Thus, when button 20 isdepressed as shown. it closes circuits II5 to H6, through the elementII4; I60 to I82 through I6I; and I88 to I10 through I69. The

button 2| on the opposite end of the toggle is then up and the onecircuit I33 to I35 is broken. Depressing button 2| causes it to make acircuit through elements I33 to I35, and button 20 on the opposite endof the toggle snaps up to break the circuits leading through it. Thus,these two buttons 2I and 20 serve as interlocks insofar as theirrespective circuits are concerned.

Taking the automatic control of the complete program of functions from Athrough B, C, D, E, F, G and back to A, the operation is as follows: Ashereinbefore referred to, the program cycle is initiated by depressingbutton I8 which may be des gnated as the program button. This starts thetelechron motor I 29 as described, whose shaft I52 makes its revolutionin 45 minutes and turns the contact arm I53 thereon slowly in aclockwise direction, and in a few seconds after line I82, line I10 toterminal M of transformer I93. Currentpassing through this circuitenergizes the coil of relay I46 whose switch closes the circuit from Nof transformer I93 through I56,

' line I51, the switch of relay I46, line IN, the coil of relay I43,line'I12 and line I10 to M of transformer I93. Thus, relay I43 closesthe main valve motor circuit from X of source I I I, through lead I I2,the switch of relay I43, leads I39 and I40 to motor I03, motorI03,'leads I31 and I38,

The energized motor I03 rotates through its shaft I02 and the gearing incase 99, thereby driving the valve shaft 85 and thereby the valve discsas previously described, the turn being made from the position offunction A to that of function B. Shaft I04 turning in unison with theshaft 95 and having thereon the cams I81, I88, I89 and I90 brings the Bfunction position of these cams under the several rollers of mercoidswitches II3, I8I, I64, I59 and I61 by counterclockwise rotation, asshown by the arrow on the cam I90. When this new position is reached,the move having been made in about ten seconds, mercoid switch H3 istilted to open; mercoid switch 'I8I is also tilted to open because ofits roller dropping into the notch of position B in cam I89; mercoidI64'isheld tilted to close by cam I88; and mercoids I59 and I81 remaintilted in their open positions by cam I81. Before the contact arm I53leaves the contact I13, which takes some 20 seconds, the main valve willhave been rotated to the B function position. In this relay switch I43,and line I32 to Y of source III.

position the mercoid I8I will break the circuit through lines I80 andI82 and then through the coil of relay I46 to open the circuit throughlines I51 and Ill and the .coil of relay I43. This will open the circuitthrough this relay I43 and thus through leads H2 and I32 and the mainvalve motor I03 to stop the latter. Since the circuit through elementsI53 and I13 at the timer will have been broken at the mercoid I6I, noarcing will result when contact I53 runs off. from I13 of the timer,

The main valve will now remain in the function B position for sometwenty minutes or until the contact arm I53 of the timer has movedaround the dial I85 to where contact I16v has been set. When contact armI53 reaches contact I16, the

circuit from N of transformer I33 leads through line I56, line I55, wipecontact I54, arm I53, contact I16, line I83, the coil of relay 1', lineI63, mercoid switch I64 (which in the B position of cam I88 is closed),line I65 and line I10 to M of transformer I33. Pigtail relay I41 nowcloses the circuit from N of transformer I33 through line I56, line,I51, line "I, the coil of relay I43, line I12 and line I10 to M oftransformer I33. Relay drops to tilt the switch and so to open thecircuit through elements I63 to I65. Opening of mercoid switch I84 takesplace before contact arm I53 passes from contact I16, as described inconnection with contact I13.

The main valve will now remain in the function C position for some twominutes or until the contact arm I53 is moved around the dial I85 towhere contact I14 has been set. When arm I53 reaches contact I14, thecircuit is completed from N of transformer I33 through line I56, lineI55, wipe'contact I54, arm I53, contact I14, line I13, the coil of relayI46, line I86, mercoid I8I (which is tilted to its closed position bycam I83 at its C position), line I82 and line I10 back to M oftransformer I33. Relay I46 closes the circuit through elements I51 to"I, the coil of relay I43, line I12 and line I10. Relay I43 closes thecircuit between lines II2 to I32 through the main valve motor aspreviously de cribed, and motor I03 turns the main valve from function Cto function D position; wherea stonis made because the roller of mercoidswitch I8I drops into the notch at D position of cam I83, tiltingmercoid I8I to break the circuit between lines I80 and I82, and thusopens the switches of relays I46 and I43.

The main valve now will remain in the D function position for some tenminutes or until the contact arm I of the timer is moved around dial I85to where contact I11 has been set. When arm I53 reaches contact I11 thecircuit is completed from N of transformer I33 through line I56, wipecontact I55, line I54, arm I53, contact I11, li'ne I83, the coil of'relay I41, 1ine I63, mercoid I64 (now closed ,by its roller on cam I88at the D position under same), line I65 and line I back to M oftransformer. I33. Relay. I41 closes the circuit through elements I51 andIll through the coil of relay I43 and lines I 12 and I10 to transformerI 33. Relay I43 again clotes the circuit through lines H2 and I32. and

motor I03 which turns the main valve from function D to function Eposition. The motor stops by break of the circuit through lines I63 andI 65 at mercoid I64, because ofthe latter being tilted to open positionas its roller drops into notch in cam I88 at the E position. Thus a stopin the E function position is in the same manner as previouslydescribed. I

The main valve will now remain in the function E position for some twominutes or until the contact arm I53 moves around the timer dial I85 towhere contact I has been set. Upon making contact of I53 to I15, thiscompletes the circuit from N of transformer I33 through line I56, lineI55, wipe contact I54, arm I53, contact I15, line I13, the coil of relayI46, line I80, mercoid switch I8I (now heldv closed by cam I83 whose Eposition is under its roller), line I82 and line I10 to M of transformerI33. Relay I46 closes the circuit through line I51, line I1I, the coilof relay I43 and line I12 to I10. This closes the motor circuit throughlines I I2 and I32, so that the motor I 03 turns the main valve fromfunction E to function F position where thenext stop is made by break ofthe circuit through lines I80 and I82 by mercoid I8I, the roller ofwhich drops into the notch of cam I83 at the F position, again making astop as previously described.

The main valve will now remain at the F function for some five minutes,oruntil the contact arm I 53 moves around the dial I85 to where contactI18 has been set. Contact between arm I53 and contact I18 completes thecircuit from N of transformer I93 through line I56, line I55.. wipecontact.'l54, arm I53, contact I18, line I83, the coil of relay I41,line I63, mercoid I64 (whose roller on cam I88 at the position F holdsmercoid I64 closed); line I65 and line I10 to M of transformer I33.'Thus relay I41 closes the circuit through line '-I51,.line "I, the coilof relay I43, lines I12 and I10. Relay I43 closes the motor circuitbetween lines H2 and I32, and motor I03 turns the main valve aspreviously described. Instead of stopping in the G function or ofiposition the motor circuit through lines H2 and I32 remains made sincethe return to service button is down to hold its three circuits' made.However when the G function position is reached the roller of mercoidswitch I64 drops into the notch of cam I88 and this would normally stopthe motor I03 in the u ual manner described above. At cam position G theelon- During the shift to the. G function position the circuit thatholds relay I41" closed is completed position of the cam I88. drop theroller of mercoid I64 to open position and to again lift and close thesame before mercoid I61 is again lifted to open. v

To hold the switch of relay I41 closed, the circuit, during this travelthrough G position, is from N of transformer I33 through line I56, lineI51, switch of relay I41 which has not yet been opened, the. pigtail ofthe switch, line I83, coil 15.

th roller of mercoid I61 is tilted out of its notch to open this circuitthe roller of mercoid I64 will have lifted out of its notch to close itscircuit, which now will be held made until the A position of the camscomes under the rollers and the roller of mercoid I64 drops in the'notchof cam I88 at the A position. Thereupon this holding circuit through thecoil of relay I41 is broken and relay I41 breaks the circuit throughline I1I, line I12 and the coil of relay I43. Relay I43 breaks thecircuit through line H2 and line I32 to the motor I03 to bring about thestop at function A position. Thus, the full series of functions from Bto A through G function position and without stopping therein has beencaused to be completed automatically by momentarily depressing the.program button I8. The timer contact arm. I53 continues on from contactI18 back to its starting point where it also stops becaue of a breakingof the circuit of motor I29 at one of the mercoids "I24 or I25 aspreviously described. The space between the setting of contact I18 andthe zero or starting point on the timer dial I85 provides for additionaltime in the periods of the several functions in case this is desired.

In case it is desired to carry the program from A automatically throughfunctions B, C, D, E and F but to stop at position G, then the programbutton I8 is depressed momentarily to start the timer as previouslydescribed, following which button U. is depressed to close its circuitthrough line I33, leg I34 of the button 2I, and line I35. Button 20 onthe opposite end of the toggle is snapped up to break the circuitthrough leg II4 between lines H5 and H6. This action also breaks thecircuits through line I60, leg I6I and line I62 and through line I68,leg I69 and line I10. -The program of functions will be carried outexactly the same as previously described except that now when thecontact arm I 53 is.

approaching the contact I18 andthe main valve is in the F functionposition of this program, as previously described, the making of thecontact between arm I53 and contact I18 completes the circuitfrom N ofthe transformer I93 through line I56, line I55, wipe contact I54, armI53, contact I18, line I83, the coil ofrelay I41, line I63, mercoid I64(whose cam I88 in the F position holds it closed), line I65and line Iback to M of the transformer I 93. Closing of relay I41 closes thecircuit through lines H2 and I32 from the source II I to the motor I03.The latter turns the-main valve from function F to function G positionwhen the notch of cam I88 in the G position drops the mercoid I64 toopen. This breaks the circuit through line I63, line I65 and the coil ofrelay I41, and the switch of the relay opens to break'the circuitthrough line I51, line "I, the coil of relay I43 and line I12. Uponbreaking the last described circuit the switch of relay I43 8 opens andbreaks the circuit through lines II2 and I32 to motor I03, therebystopping the motor.

The holding circuit through line I51, the pigtail of relay I41, lineI83,-the coil of relay I41, line I63, line I66, mercoid I61 (alsoclosed.in the G position), and line I68 to push-button 20 is open sinceleg I69 of push-button 20 is now raised. Therefore, the valve is notturned through the function G position back to the A'position describedabove in the case of a complete program,

but stops at the function G position.

This leaves the filter turned off after having been washed, and thefilter is ready to be returned to service when needed. Push-button 2| isnow down and push-button 20 on the opposite end of the toggle I9I is up.Button2l is, therefore, the shut-off button and button 20 is the servicebutton. While in this position the circuit from the source I I I throughline I I2 and mercoid H3 is open because mercoid switch H3 is open dueto its roller being raised on cam I90 in the G. position. Hence, thecircuit of program button I8 through lines 3I4 and H5, leg Il4,'line H6and line H8 or line II9, cannot be closed to thereby start a programfrom the G or off position. Also, the circuit through line II4, lineI36, the coil of relay I44, line I35, leg I34, line I33, etc., also isdead.

When stopped in the G function or shut-off position the filter may bereturned to filtering service; that is, shifted to the A functionposition, by depressing button 20 which at the same time through thetoggle I9I raises button 2|. The three bridges across the service button20 are now closed and motivating circuit from N of transformer I93 isthrough line I56, line I51, line I58, mercoid I59 (which is closed atthe G position of its cam), line I60, leg I6I, line I62, line I83, thecoil of relay I41, line I63, line I 66, mercoid I61 (also closed in theG position, mercoid I64 being open in the G position), line I68, leg I69of button 20 and line I10 back to M of transformer- I 93. Relay I41therefore closes the circuit to the coil of relay I43 which closes thecircuit through lines H2 and I32 to the motor I03, to turn the mainvalve from function G toward function A position. The mercoid I64 israised by its cam I88 to close before mercoids I59 and I61 open, so thatthe pigtail circuit through line I51, line I88, the coil of relay I 41,mercoid I 64, line I65 and line I10 to the transformer holds relay I41closed until the A position is reached, whereupon the roller of I64drops into its notch breaking the relay holding circuit and stoppingmotor I03.

When, after a program has been started, the shut-off button 2I isdepressed in order to stop at the G position, the circuit through lineI33, leg

I34, and line I 35 made by the button 2I is not completed because of theinterlocking relay I45 which has previously opened the circuit throughline I32 and line I33 when the program timer is' started. The circuitthrough line I28, the coil of relay I 45 and line I32 being in parallelwith the circuit to the timer motor I29, opens the circuit through linesI 32 and I33, and holds it open for the duration of the timed programs.This looks line II2, mercoid II3 (which is closed in the A position byits cam), line 3I4, line I36, the coil of reversing relay I44, line I35,leg I34 of pushbutton 2I,line I33, normally closed relay switch I45, andline I32to the source III. Push-button 2| snaps down holding thiscircuit made but when the G function position of the main'valve isreached the cam I raises mercoid II3 to open it. Energizing the coil ofrelay I44 closes its four-pole switch but its terminals I88 and I88leading to the motor I88 are reversed with respect toleads H2 and I82.

Push-button I8 is a function prolong button, being of normally closedtype and 'in the timer motor circuit through lines I88 and I82 it may bedepressed to open this circuit and thus stop the timer. It is providedwith lugs I82 which when the button is depressed and turned will hold itin the open circuit position until again released. Thus if the filter isin the actual washing process, say in function D, and the timer contactarm I88 is moving away from contact I14 toward contact I11, whichcontacts are set say 10 minutes apart, and it is desired to prolong thisfunction beyond 10 minutes, then button I8 may be depressed to stop thetimer and thereby lengthen the period of this function as. much asdesired.

The normal periods of the several functions may be set or reset-todesired length by shifting the contacts I14, I18; I 16, I11 and I18 tocorresponding positions along the groove I84 around the dial I88. Thepositions illustrated correspond to the timing'used in the foregoingexample.

A rsum of the operation of the push-buttons, I

the operations they control and theirinterlocking features, is asfollows:

. As shown in Fig. 18, with filter in its'on or A function position andwith service button 28 depressed:

(I) If it is desired to wash the filter and return it to the A function,program button I8 is momentarily depressed.

(2) If it is desired to wash the filter and stop the program at the offor G functlonposition, program button I8 is momentarily depressed andthen the shut-ofl button 2I is pressed down.

(3) If it is desired to return the filter to service from the G orshut-off functional position, service button 28 is pressed down.

(4) If it is desired to shut the filter off, that is, change fromfunction A to function G position, shut-off button.2l is pressed down;

(5) If it is desired to prolong any function included in the'timedprogram then while that function is in process prolong button I8 isdepressed for the length of time it is desired to add to the normalperiod of the function in question.

The interlocking features of provide fiir:

(1) Rendering all control circuits inoperative except those through theprogram button I8 and the shut-off button 2I while the main valve is inthe A function position.

(2) Rendering all control circuits inoperative except the one throughthe prolong button I8. once the program has been initiated by use of theprogram button I8. Button 2I may be depressed ,at anytime duringtheprogramto cause subsequent stoppage at G position, but the action of.button M is then to open a circuit that if left closed would laterbecome alive.

(3) Rendering all control circuits inoperative upon depressing theshut-oi! button 2I to cause shift from function A to function Gposition, and

upon reaching the G function position rendering all circuits inoperativeexcept those through the service button 28.

A mistake by the use of a wrong button does no harm because of itscircuit being dead at the time of the mistake. It is also impossible tosend a reversingpircuit to the mainvalve motor I88 while it is operatingin either direction to move, the mainvalve from one 'function toanother,

the control system As shown in Fig. 18 the start of a program isinitiated by the operator, as when the filter is seen to need washing.This initiation may however be controlled automatically to advantage.Thus instead of relying upon the operator the washing program may bestarted in accordance with a time factor determined by the timingmechanism itself. Or, the program may be started automatically from somecondition in thefilter, as upon a predetermined loss of head through thefilter.

Means for starting a program of functions automatically when apredetermined loss of head through the filter has been reached is shownin Fig. 19, in which the program button I8 which connects line IIIthrough to line H8 and line 8 as previously explained, may be depressedby a solenoid 288 mounted on the push-button frame I88. A spring I88between the retainer I81 and .the collar I84 on the upper end of thestem I88,

' tact 282 so that it may be set for any desired max imum loss of head.The loss of head indicator hand 284 is also a contactor having a hub288. and wipe contact 288. A normally open single pole relay 288controls the circuit through line I I2 and line I82 from the source IIIto the solenoid 288. The transformer I88, supplied from the source I II-' through lines I I2 and I82, delivers low voltage energy to thecircuit through lines I58 and I18, the latter being connected to contact288 so that when the lossof head corresponding to the set position ofcontact 282 is'reached the circuit will be completed through line I18,contact 288, hub 288, arm 284, contact 282, line 281, pole 2I8 ofnormally closed relay 2, line 2I8, coil of relay 288, and line I 88 totransformer I88. The relay 288' will therefore close the circuit fromsource III through line II 2 to line 2I8, coil of solenoid 288 and lineI82 to source III. Being thus energized, the solenoid 288 will actto'close the program initiating circuit 8 through leg II1 of push-buttonI8 to lines H8 or II8, starting operation as previously described.

The two poles 2I8 and 228 of the relay 2 remain closed when its coil isenergized as shown by the holding circuit from the transformer I88,

line-I18, line 22I. pole 228 of relay 2", coil 222 actuated by suitablemeans from a fioat riding on acolumn of mercury in one leg of a U-tube.One leg of such a tube, shown at 888 in Fig. 4, is connected to thefilter eflluent line on the. downstream side of the effluent .valve I2and the other leg is connected through the wall of the filter basin I8 9at a point just below the level 82 therein. Since the eflluent line fromthe filter ordinarily terminatesin a water seal in the receivingreservoir,

stoppage of flow on the closing of the efliuent valve I2 will result inthe s of head gauge tending to indicate-the diflerence in levels betweenthat in the water seal and that in its pipe connection leading from thefilter basin below the level 82, although the ,actual level in thefilter basin may be at a lower point at the completion of functions Band 0. Because there is always some loss due to flow this difference inlevels is a head greater than the loss of head attained during functionA. therefore upon 5 closing of the eiiluent valve I2, the loss of headgauge will indicate this greater head by moving its arm 204 (Fig. 19) tothe right where it will meet contact 225 This will complete the circuitfrom transformer I93, line I10, contact 206, hub 205, 10 am 204, contact225, line 226, coil 222 of relay '2I4, pole 220 of relay 2I4 and line22I back to line "0. The coil of relay 2 being thus shortcircuited anddeenergized, breaks the circuits through line 22I, pole 220 and coil 222of relay 2I4 and line 201, pole 2I3 of relay 2 and line 2II. The lattercircuit upon being thus broken lie-energizes the coil of relay 208 whichbreaks the circuit from the source III through lines M2 and I32 to thecoil of solenoid 200 thus de-ener go the latter and permitting thespring 590 of the program button 88 to break the circuit'from M6 throughleg I" to lines H8 and 9.

when the program is completed and function I A is restored then the lossof head through the 5 mark on the dial 2% will be touched by the arm 204upon its more to the left to indicate the now low head loss. This willcomplete the circuit from transformer I93, line H0, contact res, huh205, arm 20 i; contact 22?, line 22%, coil 222 of relay w 2, resistor233 of relay 2M, line 228 and line I50 to transformer I99, thusenergizing the coil :22 of relay m to close its poles are and 220, thelatter pole 220 upon closing thus complet the holding circuit from thetransformer its, line 5 HI, line ZII, pole 229 of relay E, coil 222 Oilrelay 2M, resistor 2200!,re1ay 2, line! and line I to transformer-I92.,The circuit line 201, pole 2I3 of relay, 2I4 and.iine 2Ij0, being thusclosed at the'relay 2'I4, is ready to be completed 0 through the coil ofrelay 208 to initiate the'next program when the next contact between-thearm- 204 and the contact 202 is made.

When the programs of two or more are to be initiated automatically; eachfrom prede- 'termined loss ofhead throughitebed, provision must be. madeto prevent morctlian-jone' of the filters from being washed at e time.since the flow of washwater neededto wash 'a filter ordinarily is sogreat as to preclude than one atatime.

It is not necessaryto wait until end of a program on one filter; and itsto filtering service before starting a program on a second filter. Allthatis necessary is to prevent ,two

" being in the washing function simultaneously.

Consequently the program on a. second filter may be initiated at anytime that will not cause a washinglap. The maybe so gained may not beimportant-{inn small'plant having to only a few filter unitsjl.-butj itmay become very important in a large pisntfn vmgjaconsidmble number ofbeds, Means for accomplishing this will now be described.

As shown in Figs. 20 and 21 asynchronous r'no- 75 tor-209, energizedfrom the SOIAI'W'IU W lmthe leads 2 and I32 is geared to rotate itsshaft 2I0 in a given time. A friction pinion 2I6 (see Fig. 21) slidablymounted on the shaft 2 I 0 is held in any position along the shaft 2H)by the set screw 2". A friction disk 2I8 on the shaft 2 5 is rotated bythe friction pinion 2I6 and may, by

adjustment of the latter along its shaft 2I0 be set to make a revolutionin the time taken to complete two or more programs of functions or partsthereof as from B to E, depending upon 10 the number of filters in the,battery. If the timing of the functions is shortened, thenthe frictionpinion 2I6 may be adjusted to the left along the shaft 2I0 to correspondwith the shortened period, or vice-verse. Thus for example, with abattery of two filters for which Fig. shows the control, the dial 2I8 isprovided with two contacts 229 and 230, and the continuous rotation ofthe hand contactor 2 I2 on the shaft 2I I provides for completing thecircuit through line 20 I56 frorn the transformer I93 alternately tocontacts 229 and 230 every32 minutes, or in a greater or lesser time,depending upon the adjustments explained previously. .Obviously, forthree or J more filters there would be a corresponding numbar ofcontacts on the dial 2I8 equally spaced and with the time allowanceproperly adjusted.

In Fig. 20 elements 20I and 23i are the loss of head indicators for.'filters Nos. 1 and 2 (not shown). Elements 200 and 232 are thesolenoids for operating the program push-buttons of two I filters. Thesebuttons operate as explained in groove 209. The contact 202 is elongatedso that if am 204 reaches it just after the arm 2I2 has passed contact229, 204 will remain on 202 until 2I2 again reaches 229 eventhough therebe increase in loss of head during this period. When I completed, thecircuit from transformer I93. passes through line I56, arm 2I2 andcontact 229 of the selector interlock, line 233, coil of relay 200, line2 I5, pole 2I3 ofrelay 2I4, line 201, contact 202, arm 204 now incontact with same, hub 205, contact 206, and line I10 to transformerI93. This low voltage circuit therefore energizes the coil of relay 200which closes its normally open switch thereby completing the highvoltage circuit from the source III through lines H2 and 2I'0 to coil ofsolenoid 200 and line I32 to source III. The solenoid 200 being thusenergized closes the program initiating circuit for filter No. 1 asexplained in connection with Fig. 19.

The circuit'through the coil of relay 200 is soon broken by the arm 2I2ofthe timer moving 00 past the contact 229. Upon the completion 'offunction 0 of the program for filter No. 1, the effluent valve is closedand as previously explained, the loss of head gauge dial "I willindicate a higher value thereupon bringing the arm 204 into 05 contactwith 225. This will complete the circuit from transformer I93 throughline 110, pole 220,

v coil 222 hi relay 2", line 228, contact 225, arm

204', hub 205, contact 209 and back to line "0, thus shortcircuiti-ngthecoil 222 of relay 2I4. The coil 222 of relay 2 being thusde-energized opens the poles 2I3 and 220 of relay 2, thus breaking thecircuit from contact 202 through" ,line 201 to line 2I5 and also theholding circuit of relay 2 from transformer I03, line I" and:

the transformer I93.

pole 228 of relay 2, to the coil 222 of same.- when the program offilterNo. 1 is completed and function A is restored, the loss ofheadbeing now greatly reduced, the arm 204 of the gauge I will move tothe left toward the zero mark. In so doing, contact will be made betweenthe arm 204 andthe contact 202, but the initiating circuit for anotherprogram will not be completed even though the arm 2I2 of the timershould at the same instant be in contact with 229 because the coil 222of relay 2 being de-energized, the pole 2I3 of relay 2. is open. Furthermovement of the arm 204 to the left brings it to contact 221 setjustabove the zero mark on the dial 20I. This completes the circuit fromtransformer I93, line I10, contact 206, hub 205, arm 204, contact 221,line 228, coil 222 of relay 2, resistor 223, line 234 and line I56 totransformer I93. Relay 2I4 thus closes its two poles, pole 220 closingthe holding circuit from transformer I93,.line I10, pole 220 to coil222, resistor 223, line 234and line I56 to transformer I93. The otherpole 2I3 closes the circuit line 201 to line 2I5 so that it may becompleted when, next the contacts between 204 and 202 and between 2I2and229 of the interlock are both made to initiate the following programfor filter No. 1.

The washing program of filter No. 1 will be completed before the. timerarm 2I2 moves from contact 229 to contact 230, but if during this timefilter No. 2 builds up a loss of head sufiicient to bring the arm 235 ofits loss of head gauge 23I in contact with the elongated adjustablecontact 236, initiation of the washing program of filter No. 2 will beheld in abeyance until the timer arm 2I2 reaches, contact 230. When arm2I2 of the selector now reaches. contact 230, the circuit is completedfrom the transformer I93, line I10, contact 238, hub 231, arm 235,contact 236, line 240, pole 244 of relay 243, line 241, coil of relay250, line 249, contact 230, arm 2I2 and line I56 to Relay 250' closesits switch completing the' circuit from the source III through lines II2 to I, coil of solenoid 232 and line I32 tosource III. fore closes theprogram initiating circuit by depressing the program button I8 of filterNo. 2 in the manner shown by and described in connection with Fig. 19.

The completion of function G of the program of filter No. 2 brings theeflluent valve of that filter to its closed position resulting in anincreased movement of the loss of head arm 235 to the right, aspreviously explained, such that the shorting circuit for the coil 246 ofrelay 243 is completed from transformer I 93 through line I10,

contact 238, hub 231, ar'm235, contact 252, line 239, coil 246 of relay243, pole 245 of relay 243,

and line 248 back to line I10, thus de-energizing the relay coil 246 andbreaking the holding circuit line 248, to coil'246 of relay 243 atpole245.

Also; circuit line 240 to line 241 is broken at pole 244 of relay 243 sothatupon return of the loss of head gauge arm 235 toward the zero markits contact with 236 in passing same will be unable to complete the lastmentioned circuit through relay 243 to initiate another program uponreturn of filter No. 2 to function A. Upon the arm 235 reaching contact2 set just above the zero mark, the circuitto re-energize the coil 246-of relay 243 is completed from transformer I93, line I10, contact 238,-hub 231, arm 235, contact 2, line 242, coil 246 of relay 243, resistor253,'line 234 and line I 56 to transformer I93. The relay 243 thuscloses its poles 244 and 245, pole The solenoid 232 there- 245 closingthe holding circuit from transformer I93, line I10, line 248, pole 245,coil 246, resistor 253, line 234 and line I56 to transformer I93, andpole 244'closing the circuit line 241 to line 240 so that it may becompleted to initiate the next program when arm 235 again makes contact'with 236 on the loss of head gauge 23I, and interlock arm 2I2 makescontact at 230.

It will be apparent from the preceding that once the contact at the lossof head gauge for a filter is made, that filter will, have its programinitiated at the beginning of the next period allotted to sameby theinterlock timer. Also since the time intervals for the two filters areof 'sufiicient length and alternate with each other,

,the washing periods allowed for all the filters before its turn againarrives, although none of the other filters may need washing. This lossof time is overcome by the form shown in Fig. 22.

Referring now to Fig. 22 the motor 209 is geared to drive the shaft 2I0and the selector arm 2| 2 thereon at a relatively rapid rate so thatcontact will be made with one of the contacts on disk 2I8 at intervalsof a few seconds, there being one of the latter contacts. for eachfilter, three being shown.

The motor 209 receives power from the source III through line II2, pole286 of relay 284, line 285 and back to III through line I32.Transformer. I93 connected to the source I II through lines H2 and I32,provides low voltage energy to hold the coil 288 of relay 284 energizedthrough line I10, line 289, pole 281 of relay 284, coil 288, resistor282, line 283 and line I56 to transformer I93.

Loss of head gauge 20I and starting solenoid 200 are associated withfilter No. 1, whose 'selector dial contact is 251. Another loss of headgauge 23I and starting solenoid 232 are associ,

ated with filter No. 2, whose selector dial con-.

tact is 258. And another loss of head gauge 210 and starting solenoid254 are associated with filter ,No. 3, whose selector dial contact is259.

Assuming now that filter No. 3 has built up a loss of head that movesthe arm 263 on its loss of head gauge dial 210 over to the elongated andadjustable contact 264, following which the selector arm 2I2 reaches theselector dial contact 259.

This will complete the circuit from transformer I93 through line I10,contact 260, hub 26I, arm 263, contact 264, line 265, pole 213 of relay21I, line 219, selector contact 259, arm 2I2, line 28I, coil 288 ofrelay 284, pole 281 of relay 284, and line 289 back to line I10, thus-short-circuiting the coil 288 of relay 284. The

poles of relay 284 therefore will open, thus breaking the shortingcircuit through the pole 281 from the coil 288 of relay 284, and alsothe circuit '2 from the source III to line 285 and the motor 209 at thepole 286 of relay 284. The motor 209 therefore will stop when selectorarm 2I2 makes contact with 259, with arm 263 of the loss of head gauge210 in contact with 264.

It will be'noted also that when'the above-mentioned circuit is-completedfrom transformer I93 through line I10, contact 260, hub 26I, arm 263,contact 264, line 285, pole 213 of relay 21I, line 219, contact 259 toarm 2I2, and thence to line 28I, a circuit'is alsomade through arm 2I2to contact 303 on dial 2I8 to line 280, coil of relay 255, line 256,line 234 and line I58 to transformer I93. Relay 255 closes its switch,completing the circuit from source I through line II2, switch of relay255, line 306, coil of solenoid 254 and line I32 to source III. Thusen'ergized, the solenoid 254 acts to operate the program button I8 offilter No. 3 in the manner shown andvdescribed in connection with Fig.19.

Referring in Fig. 22 to the relay 21I, it will be noted that the circuitholding its coil energized to keep its poles closed is from transformerI93, line I10, pole 214 of relay 21I, coil 212, resistor 308, line 234and line I 56 to transformer I93. v v v The washing program 01' filterNo. 3 having been initiated as explained above, is now carried out whilethe motor 209 remains stopped with selector arm 2I2 remaining in contactwith contacts 259 and 303. At the end of function C in the program offilter No. 3 the closing of its eflluent valve, I2 (see Fig. 4) willresult in the arm 263 of its loss of head gauge 210 moving to the rightfor the reasons previously explained.

Arm 263 will thereupon contact with 266 completing the circuit fromtransformer I93, line I10, contact 260, hub 26l, arm 263, contact 266,line 261, coil 212 of relay 21I, pole 214of relay 2" and back to lineI10, thus short-circuiting the coil 212 of relay 21I, which thereuponopens its two poles 213 and 214 breaking the circuits leading from thesetwo poles to line I and to line 219 respectively. Breaking the circuitthrough 219 interrupts the circuit through the latter to the selectorcontact 259, arm 2I2 to line 28I; also the circuit through arm 2I2 tocontact 303 and line 280 to the coil of relay 255 thus de-energizing thelatter to open its switch in'the line II2 to line 306 to de-energize thecoil of solenoid 254. Thus the program button I8 of filter No. 3 isreleased.

In the further course of its program the main control valve for filterNo. 3 will move to func-.

tion E to terminate the actual washing operation. In so doing, a rotaryswitch 296 (Fig. 22) whose arm 292 is attached to its shaft I04 (seeFigs.

; 16 and 17) will make contact betweenarm resistor282, line 283 and lineI56 to transformer- I93, and pole 286 will close the circuit from the.source III, line II2, pole 286, line 285, motor 209 and line I32 tosource III, thereupon starting the-motor 209 which .now resumes drivingthe selector as before.

Filter No. 3 will have its program terminated in due course by return tofunction A whereupon as previously explained in connection with Fig.

19, the loss of head gauge will move its arm 263 toward its zeroposition. In so doing it will pass contact 264, but. this will notcomplete the ,cir-' cuit therethroughbecause the poles of relay 21I areat this :tim'e -open and thus thepremature initiation of another programcannot take place. even though the contact between, 253' and 264 shouldtake place at the exact moment the selector arm 2I2 passes contacts 259and 303.

In moving toward the zero mark of the gauge 210 the arm 263 afterpassing'the contact 254 will shortly reach contact 268 set to the rightof the zero mark a short distance. This will comwill complete theholding circuit from trans-' former I93, line I10, pole 214, coil 212,resistor 308, line 234 and line I56 to transformer I93. Pole 213 willclose the gap between line 265 and line 219 but the circuit in whichthese are com-- prised will not again be completed to initiate a washingprogram for filter No. 3 until its loss of head gauge arm 263 againreaches contact 264 and also the selector arm 2I2 reaches contacts 259and 303.

If, during the washing program of filter No. 3 the loss of head of sayfilter No. 2 has built up so that the arm 235 of its loss of head gauge23I has moved up to the contact 235, the washing program of filter No. 2will be held inabeyance and it will remain in filtering service becauseat the time the selector motor 209 will not .be run ning and the circuitfrom transformer I93, line I10, contact 238, hub 231, arm 235,contact236, line 240, pole 244 of relay 243, line 211, selector contact258 to arm 2 I 2 of selector cannot be completed.

When the washing function E of filter No. 3 is completed and the motor209 again started as above referred to, selectorarm 2I2 moves clockwiseaway from contacts 259 and 303 and soon reaches contacts 251 and Iassociated with filter No. 1. The circuits from arm 2I2 to contacts 251and 30I can not now be completed because the loss of head of filter No.l is not sufiicient at the time to bring the'arm- 204 of dial 20Iassociated with filter No. 1 into contact with 202. The motor209'therefore continues to run and in a few seconds selector arm 2I2reaches contacts 258 and 302 associated with filter No. 2, whereupon thecompletion of the oil circuit to relay 284 will stopthe motor 209 andthe completionof the circuit through the coil of relay 250 will resultin energizingthe solenoid 232 and the .operation of program button I8associated with filter No. 2.

-It will be understood from Fig. 22 that the .rotary switches 294, 295and 296 are associated respectively with filters Nos. 1, 2 and 3, andthat the program initiating circuit for anyone of the filters that isclosed at its loss ofhead gauge is completed only when the selector arm2I2 reaches the selector contact associated with that filter and thatsimultaneously with the completion of any filter program initiatingcircuit the selector motor stops and-remains stopped until the actualwashing operation of that filter (function E) is finished. Thereupon therotary switch associated with that filter causes the closing of

